Woocommerce Membership Hook

Hello ,

for a project where is installed the woocommerce membership and woocommerce sensei i need to change the expiration date of the membership, after the order complete, with a script that I have correctly configured. My script work well if I change manually the order status (ex. from pending to complete). Instead, I need it to run automatically and only after the membership is created, because if it is executed before not finding the active membership it would return value 0.
So I would need to know which is the hook of the membership that activates it on the system in order to hook my command in queue to this last one.